What are vaccines?

What are vaccines?

Vaccines are products that protect people against serious and potentially deadly diseases. Unlike most medicines that treat or cure diseases, vaccines prevent them. On this site, you can learn what vaccines are, how they work, and why they are important.

You will see the terms vaccines, vaccinations and immunizations used across this site. The following is a simple guide to help you remember their definitions:

Vaccines are products that produce immunity to a specific disease. Most vaccines are given by injection (needle) but some are given orally (by mouth) or nasally (sprayed into the nose). “Researchers have been working on a new vaccine against Zika virus.”

Vaccination is the act of introducing a vaccine into the body to produce immunity to a specific disease. “I am taking my child to get vaccinated against HPV."

Immunization is the process by which a person or animal becomes protected against a disease. This term is often used interchangeably with vaccination.

“Vaccines cause immunization."

What does immunity mean?

Immunity is protection from a disease. If you are immune to a disease, you can be exposed to it without becoming sick.